This proposal is submitted in response to PA-03-044 (Risk Factors for Psychopathology Using Existing Data Sets) to carry out comprehensive centralized secondary analyses of risk factors in the World Health Organization World Mental Health (WMH) surveys. The WMH surveys are a coordinated set of community psychiatric epidemiological surveys in 27 countries with a combined sample size of nearly 200,000 respondents. The diagnostic instrument is an expanded version of the WHO Composite International Diagnostic Interview (CIDI). The interviews also include a rich risk factor battery. The surveys are all being carried out by carefully trained and closely monitored lay interviewers, with centralized training and quality control monitoring used to maximize comparability of data across sites. Clinical reappraisal interviews using the Structured Clinical Interview for DSM-IV (SCID) are being administered to sub-samples in a number of sites to confirm the CIDI diagnoses. Most of the 27 surveys are funded only to assess the within-county societal burden of mental disorders, unmet needs for treatment, and barriers to obtaining treatment. Within country analyses are largely limited to preparing government reports on these basic issues. None of the survey teams is funded to carry out cross-national comparative analyses. We propose to capitalize on this under-use of the WMH data by carrying out centralized secondary analyses in collaboration with the international WMH investigators. These secondary analyses will focus on six lines of research, all of which have been of long-standing interest to psychiatric epidemiologists: (1) sex differences in mental illness; (2) the association between social class and mental illness; (3) patterns and effects of assortative mating on the course and intergenerational transmission of mental illness; (4) the long-term effects of childhood adversities on adult mental illness; (5) the effects of temporally primary early-onset mental disorders on the onset and course of subsequent secondary mental disorders; and (6) the role of PTSD in mediating the effects of traumatic life events on other types of mental illness. The unprecedented size and substantive richness of the WMH database will allow important contributions to be made in each of these six areas of investigation. [unreadable] [unreadable]